Optical fiber sensors are often utilized to obtain various surface and downhole measurements, such as pressure, temperature, stress and strain. Examples of optical fiber sensing systems include distribute sensing systems that utilize Rayleigh backscatter to measure downhole parameters, e.g., temperature and strain. One application of optical fiber sensors in downhole environments is distributed acoustic sensing (DAS). In DAS, spatial changes in optical signals scattered by an optical fiber are caused by the impingement of acoustic waves hitting the fiber and are detected by an interrogator capable of recognizing the changes based on scattered optical signals and deducing the acoustic signals.
Single mode optical fibers are often used in downhole environments for, e.g., communication and measurement of parameters of a downhole environment (e.g., parameters of a formation, a borehole, borehole fluid and/or parameters of downhole components). Many characteristics of the particular fiber used can affect the quality or ability to measure a desired parameter, including but not limited to the mode size, optical loss in the fiber, and dispersion of the fiber (which causes a spreading of optical pulses in time). Challenges involved in performing downhole measurements include limits on optical signal power due to non-linear effects that can occur at higher powers and compromise the effectiveness of such measurements.